Bluetoothcommunication - modify input string

Hi Arduino-Community,

currently I'm programming a little program where i can send a string to a Bluetoothmodul which is on my Arduino Uno. I'm sending this strings by an android app.

The string is like: "r255g123b77"

Is it possible to split this string into 255, 123 and 77 and spot what number refers to what character?

For example i need something like: String a = 255; String b = 123; String c = 77;

in the end, and then i will convert them to integers.

A rapid response would be appreciated.

Best wishes, maetho ;)

Look into strtok() and atoi()

sometimes it is easier to figure out how to format the data being sent by figuring out how to decode it when received. The below code is for servo control, but the send/receive format might be of interest. In this setup the numeric value is first, followed by the data identifier, followed by an end of data delimiter. If you want to stick with the “r255g123b77” format you can use some simple String functions to parse the data packet. Adding an end of data delimiter such as a comma will help separate multiple data packets.

//zoomkat 8-04-12
//simple button GET server code to control servo and arduino pins 5, 6, and 7
//for use with IDE 1.0
//open serial monitor to see what the arduino receives
//use ' instead of " in the html 
//address will look like when submited
//for use with W5100 based ethernet shields
///note that the below bug fix may be required

#include <SPI.h>
#include <Ethernet.h>

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED }; //physical mac address
byte ip[] = { 192, 168, 1, 102 }; // ip in lan
byte gateway[] = { 192, 168, 1, 1 }; // internet access via router
byte subnet[] = { 255, 255, 255, 0 }; //subnet mask
EthernetServer server(84); //server port

String readString; 


void setup(){

  pinMode(5, OUTPUT); //pin selected to control
  pinMode(6, OUTPUT); //pin selected to control
  pinMode(7, OUTPUT); //pin selected to control
  pinMode(8, OUTPUT); //pin selected to control
  //start Ethernet
  Ethernet.begin(mac, ip, gateway, gateway, subnet);

  //enable serial data print 
  Serial.println("server multi pin button test 1.0"); // so I can keep track of what is loaded

void loop(){
  // Create a client connection
  EthernetClient client = server.available();
  if (client) {
    while (client.connected()) {
      if (client.available()) {
        char c =;

        //read char by char HTTP request
        if (readString.length() < 100) {

          //store characters to string 
          readString += c; 

        //if HTTP request has ended
        if (c == '\n') {

          Serial.println(readString); //print to serial monitor for debuging 

          client.println("HTTP/1.1 200 OK"); //send new page
          client.println("Content-Type: text/html");

          client.println("<TITLE>Arduino GET test page</TITLE>");

          client.println("<H1>Zoomkat's simple Arduino button</H1>");
          // For simple testing, pin 5, 6, 7, and 8 are used in buttons
          // DIY buttons
          client.println("<a href=/?on2 >ON</a>"); 
          client.println("<a href=/?off3 >OFF</a>"); 
          client.println("&nbsp;<a href=/?off3579 >ALL OFF</a>


          // mousedown buttons
          client.println("<input type=button value=ON onmousedown=location.href='/?on4'>"); 
          client.println("<input type=button value=OFF onmousedown=location.href='/?off5'>");        
          client.println("&nbsp;<input type=button value='ALL OFF' onmousedown=location.href='/?off3579'>

          // mousedown radio buttons
          client.println("<input type=radio onmousedown=location.href='/?on6'>ON</>"); 
          client.println("<input type=radio onmousedown=location.href='/?off7'>OFF</>"); 
          client.println("&nbsp;<input type=radio onmousedown=location.href='/?off3579'>ALL OFF</>

          // custom buttons
          client.print("<input type=submit value=ON style=width:100px;height:45px onClick=location.href='/?on8'>");
          client.print("<input type=submit value=OFF style=width:100px;height:45px onClick=location.href='/?off9'>");
          client.print("&nbsp;<input type=submit value='ALL OFF' style=width:100px;height:45px onClick=location.href='/?off3579'>");

          //stopping client

          ///////////////////// control arduino pin
          if(readString.indexOf('2') >0)//checks for 2
            digitalWrite(5, HIGH);    // set pin 5 high
            Serial.println("Led 5 On");
          if(readString.indexOf('3') >0)//checks for 3
            digitalWrite(5, LOW);    // set pin 5 low
            Serial.println("Led 5 Off");
          if(readString.indexOf('4') >0)//checks for 4
            digitalWrite(6, HIGH);    // set pin 6 high
            Serial.println("Led 6 On");
          if(readString.indexOf('5') >0)//checks for 5
            digitalWrite(6, LOW);    // set pin 6 low
            Serial.println("Led 6 Off");
           if(readString.indexOf('6') >0)//checks for 6
            digitalWrite(7, HIGH);    // set pin 7 high
            Serial.println("Led 7 On");
          if(readString.indexOf('7') >0)//checks for 7
            digitalWrite(7, LOW);    // set pin 7 low
            Serial.println("Led 7 Off");
            if(readString.indexOf('8') >0)//checks for 8
            digitalWrite(8, HIGH);    // set pin 8 high
            Serial.println("Led 8 On");
          if(readString.indexOf('9') >0)//checks for 9
            digitalWrite(8, LOW);    // set pin 8 low
            Serial.println("Led 8 Off");
          //clearing string for next read